program Project2;

{$APPTYPE CONSOLE}

uses
  SysUtils;
var
  arr : array[1..100,1..100]of byte;
  used : array [1..100] of boolean;
  q : array [1..100] of integer;
  otvet : array[1..100] of integer;
  p: array [1..100]of integer;
  p1: array [1..100]of integer;
  i, l, r, n, s, f, j, sum, summa : integer;
  procedure BFS(n, s, f : integer);
    begin
      l:=1;
      r:=1;
      q[r]:=s;
      otvet[s] := 0;
      used[s]:=true;
      while l <= r do
        begin
          for i := 1 to n do
            begin
              if (arr[s,i]=1) and (not used[i]) then
                begin
                  inc(r);
                  q[r] := i;
                  used[i] := TRUE;
                  otvet[i] := otvet[s]+1;
                  p[i]:=s;
                end;
            end;
          inc(l);
          s := q[l];
        end;
    end;
begin
  reset(input,'path.in');
  rewrite(output,'path.out');
  read(n);
  summa:=0;
  for i := 1 to n do
    begin
      for j := 1 to n do
        begin
          read(arr[i,j]);
        end;
    end;
  read(s,f);
  if s=f then
    begin
      writeln(1);
      write(s,' ',f);
    end;
  for i:=1 to n do
    begin
      used[i]:=false;
    end;
  BFS(n,s,f);
  if used[f]= false then
    begin
      write(-1);
      exit;
    end;
      writeln(otvet[f]);
      p1[1]:=f;
      sum:=f;
      for i:=1 to otvet[f] do
        begin
          p1[i+1]:=p[sum];
          sum:=p[sum];
        end;
      for i:=otvet[f]+1 downto 1 do
        begin
          write(p1[i],' ');
        end;
  readln;
  readln;
end.